Effect of punch shape on granular flow and rearrangement during powder compaction studied by X-ray microtomography

S.A. McDonald, P.J. Withers

Manchester X-ray Imaging Facility, School of Materials, University of Manchester, Manchester M13 9PL, UK

Abstract

X-ray microtomography has been used to study particle rearrangement during indentation of a model granular material in situ. The 3-D flow characteristics of mono-sized glass spheres have been followed within a die as a function of the displacement of a punch. The response due to three different punch shapes is compared: a flat punch, an angled punch and a rounded punch. Digital volume correlation (DVC) has been employed to follow local 3-D displacements of the particles (without added markers) to reveal bulk granular movement. The deformation fields associated with the particle displacements are calculated, allowing observation of resulting dilatation.

Keywords: Soil mechanics; powder compaction; microstructure evolution; digital image correlation (DIC)